The construction work of the Patna Metro Rail project is in full swing. It achieved a major breakthrough on Monday after the first of four Tunnel Boring Machines (TBM) – ‘Mahavir’ was lowered at Moin-Ul-Haq metro station with a drive length of 1,494 m towards Patna University station. With this, the tunneling work of Patna Metro commences for the first time. The underground tunneling work will be done using the TBM machine.
About TBM ‘Mahavir’:-
The TBM ‘Mahavir’ has a weight of around 420 MT i.e. equivalent to that of 60 elephant’s weight. It comprises a cutter head, front shield, middle shield, and tail shield along with the backup gantries. The main body length of the TBM is around 9 m with EPB full length of about 95 m. The excavation diameter is 6,650 mm, with the precast ring lining with an outer diameter of 6,350 mm and inner diameter of 5,800 mm. These TBM machines have been designed and manufactured by the China Railway Construction Heavy Industry Corporation Ltd (CRCHI).
How TBM ‘Mahavir’ was lowered at Moin-Ul-Haq station?
The TBM Mahavir bearing serial number DZ1090 was first assembled at the ground and then it was lowered with the help of Mega Lifts on the cradle. It was lifted using strand jacks with a capacity of 325 MT each. A total of four strand jacks have been used to lower the TBM at the metro station. The Mega lift will lift the cradle and then push it up to TBM lowering position (Launching Shaft). Then TBM will be lowered into the shaft which is 16 m (approx) below the ground level after skidding.
The foundation stone of the Patna Metro Rail Project was laid by Prime Minister Narendra Modi on February 17, 2019, at an estimated cost of Rs 13,365 crores. It will have two corridors – (a) Danapur to Mithapur and (b) Patna Railway Station to New ISBT. On completion, the Patna Metro project will ease the public transport in the city and its adjoining areas.